Communities are “coming together, we will not allow them to divide us”, said Sir Richard Lees, the leader of Manchester city council, as my home town began a struggle to come to terms with an atrocity designed to provoke retaliation. “We are strong,” said Andy Burnham, the mayor of Greater Manchester. “Our values, our country and our way of life will always prevail,” said the prime minister.

Before I go further, I should say the politicians were broadly right. The stereotype of warm northerners is overdone. Mancunians can be as vicious as anyone else. But a Londoner does not have to spend too much time in Manchester to notice a convivial willingness to talk to strangers that is absent from the capital. As much as the pictures of dead girls, as much as the relief at finding that my niece, an Ariana Grande fan, had decided to give the concert a miss, the stories of taxi drivers giving free rides to the injured, the lawyers offering free advice and the cafe owners proffering free meals to the emergency services floored me. Manchester is not a city being torn apart by hatred.

Nor is Britain a country on the edge of civil war. Online jihadis celebrated the bomber as a “lion”, but there were no blood-maddened celebrations here. Donald Trump in the US and Marine Le Pen in France would have exploited the mass murder to arouse ethnic and sectarian hatred. Our far right does not include actual and potential presidents. Instead, we have Allison Pearson from the Telegraph calling for internment and Katie Hopkins gabbling about a “final solution” to the Muslim problem like a Devon Eva Braun. These are marginal figures, for all fuss made about them.

But warm words about “our way of life prevailing” rub up against scratchy questions about what our “life” is now and which way it is taking. Talk to anti-Islamist Muslim writers and activists and they are worried. They don’t see “diversity” and “community”, those warmest of 21st century words, as synonyms but opposites. No one knows the level of Islamic State support in Britain, they say, but with MI5 monitoring 3,000 suspects it isn’t negligible. Beyond the violent and potentially violent lie fractured and isolated ghettos, where large numbers are prey to religious demagogues.

Shiraz Maher, of King’s College London, points me to a paradox. If you measure success in business, the professions and politics, Muslims do better in Britain than in any other European country. But those who get on have little influence. Those who are left behind listen to Islamists who tell them that the west is decadent. Rabbil Sikdar, a liberal Muslim friend and Labour activist, is equally bleak. Many Muslims just don’t see Britain as their home, he wrote after the attack. “It’s why they’re more obsessed with Palestine than the NHS and why integration of Muslims is so poor. We culturally isolate ourselves because to integrate is to apparently lose your Muslim identity and become western.”

Fiyaz Mughal runs the Tell Mama civil rights group. As it monitors attacks on Muslims you might have thought its enemies were all of the Katie Hopkins variety. But its activists are as likely to be denounced by Islamists at Muslim Engagement and Development (Mend) for being “phony” Muslims as they are to be denounced by the Telegraph. Their crime, their break with Muslim values, is allying with Jews and gays in the fight against prejudice. Mughal, too, tells me has no doubt that Mend and groups like it are winning the battle for Muslim minds.

They have certainly won the battle to control Labour policy. Labour either does not know that extremists want to stop anti-extremism policies or knows but does not care. It is promising to review the Prevent anti-extremism initiative. Burnham went further last year and demanded that it be scrapped. Think of that. The mayor of a city that was to be attacked by a suicide bomber damning as “toxic” a strategy that aims to stop Muslim teenagers being groomed online by Islamic State and white teenagers being groomed by neo-Nazis. It’s as if he had condemned “toxic” social workers for trying to keep children from paedophiles.

On the other side of the coin, the comforting notion that anti-Muslim bigotry is confined to a handful of click-seeking media whores does not hold. Look at the Conservative press or read the output of Tory thinktanks and you can suspect that liberal conservatism barely exists today. I accept that absence of evidence is not evidence of absence. But if you watch for the arguments that aren’t made and the fights that aren’t picked you will notice that mainstream conservatives greet anti-Muslim bigotry with silence.

There is no debate on the right about the dangers of toppling over into the sectarian politics of a Trump or Le Pen. On racial hatred as much as on Brexit you can wait forever for a liberal Tory dog that never barks. Beyond that, and as destructively, the Conservatives have no plans to slow the growth of faith-based schools, which segregate children by religion and, more often that not, race. The cause of secular education, like support for the single market and opposition to anti-Muslim bigotry, is an idea whose time appears to have gone on the right.

I don’t wish to sound alarmist. There is no conveyor belt that picks up believers in reactionary religion and transports them to religious violence. You can spend your life believing women should be second-class citizens and homosexuality and apostasy are crimes that in an ideal Islamic state deserve the death sentence and never harm anyone apart from your wife and children. Equally, desegregating the school system is a modest reform, not a panacea. As for the silence of mainstream conservatives, I am sure that if Theresa May is re-elected she will not call for a Muslim travel ban.

But if you believe ideas have power, then you must believe in the power of bad ideas to harm when they are left uncontested. Liberal Muslims suffer from the widespread belief that to be “liberal is a contradiction of the faith”, as Rabbil Sikdar put it. With honourable exceptions, white liberals prefer the safe life and hold that it is “Islamophobic” to help their cause and argue their case. Liberal conservatives say nothing because they fear their party leadership won’t support them and know the rightwing press will denounce them. They too cede the field without striking a blow.

“Our values will prevail,” says Theresa May. No they won’t. Not if no one is prepared to say what they are, let alone prepared to fight for them.• Comments will be opened later